It is often important to “connect” electronic devices together, establishing a communications link between the electronic devices, such as for transferring data between the devices, or simply communicating between the two devices. Exemplary data being transferred between devices may comprise a media file (such as an image file, an audio file, a video file), DRM (digital rights management) protected content, an OS (operating system) update, customer specific code, OEM (original equipment manufacturer) specific code, retail specific code, a firmware image for the destination device, user data, encryption/decryption keys (codes), electronic funds transfer (EFT) data, static data and the like.
In the descriptions set forth herein, one of the devices participating in a communications link may be referred to as a “source” (or sending) device, and the other device may be referred to as a “destination” or “sink” (or receiving) device. One of these devices may also be referred to as a “partner” device. However, it should be understood that data may be transferred in either, or both directions between the two devices.
Some examples of electronic devices which may benefit from the techniques disclosed herein may include, but are not limited to cell phones (or handsets, or smart phones), computers, laptops, tablets, or comparable electronic devices.
Typically, the communications link between two devices comprises a cabled connection or a wireless connection. A cabled connection such as USB (Universal Serial Bus) is typically point-to-point, and requires mechanical connectors at each device, and a cable between the devices (one of which devices may be a “hub” connecting point-to-point with several other USB-enabled devices). A wireless connection such as WiFi or Bluetooth operates in more of a “broadcast” mode, where one device can communicate simultaneously with several other devices, over a RF (radio frequency) link, typically in the range of 700 MHz-5.8 GHz.
Mechanical connectors are “passive”, and therefore offer no additional features and capabilities with respect to the state of the connection. Generally, either the connection is working, or not. The terms “Host System” or “Host IC” refers to a device or part of a device that may include an integrated circuit(s) that implements the functionality necessary to communicate with a connector. The host system behind the connector may perform some initial analysis (including detection and enumeration of connected devices) in setting up the communications link, which may be a time-consuming process and, generally, after the link is established, no more testing is performed, the link simply operates, until it fails. After link failure, a host system may be programmed to attempt to re-establish the connection, which can be a cumbersome process.
Mechanical connectors are at risk for breakdown either due to wear and tear or due to the use of inappropriate force applied when inserting/de-inserting the connectors. The risk of failure coupled with the fact that mechanical connectors are expensive to manufacture makes the use of mechanical connectors expensive.
The use of a multitude of connectors for transferring different protocol data is cumbersome since a different cable and/or connector will typically be needed for each protocol data transmission. The length of cable that can be used is also limited since transferring data at multi-Gbps through a long cable creates signal reliability issues at the receiver, which could be compensated for either on the transmitter or receiver ends but increases the power dissipation and system complexity.
A wireless connection such as WiFi or Bluetooth operates in more of a “broadcast” mode, where one device can communicate simultaneously with several other devices, over a RF (radio frequency) link, typically in the range of 700 MHz-5.8 GHz.
In the main hereinafter, point-to-point connection-oriented techniques for data transfer between two electronic devices will be discussed. An illustrative example of a point-to-point, wireless connection-oriented communications link for transferring data between electronic devices is Near Field Communication (NFC). NFC implements a set of standards for smartphones and similar devices to establish radio frequency (RF) communication with each other by touching (“bumping”) them together or bringing them into close proximity with one another.